Compilare: user.cpp: In function ‘void df(int)’: user.cpp:18:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[x].size();i++) ~^~~~~~~~~~~~ user.cpp: In function ‘void df2(int)’: user.cpp:32:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v1[x].size();i++) ~^~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:98:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<v2[i].size();j++) ~^~~~~~~~~~~~~ user.cpp:100:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j1=0;j1<v2[i-1].size();j1++) ~~^~~~~~~~~~~~~~~ user.cpp:137:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<v2[i].size();j++) ~^~~~~~~~~~~~~ user.cpp:139:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j1=0;j1<v2[i-1].size();j1++) ~~^~~~~~~~~~~~~~~